A substrate processing process in which a thin film is formed by chemical vapor deposition (CVD) is performed using, for example, a substrate processing apparatus that includes a process chamber configured to accommodate and process a plurality of substrates therein, a process gas supply line via which a process gas is supplied into the process chamber, and an exhaust line via which the inside of the process chamber is exhausted. In this case, a thin film is formed on the plurality of substrates by supplying the process gas into the process chamber via the process gas supply line while the inside of the process chamber in which the plurality of substrates are accommodated is exhausted using the exhaust line, and causing the process gas to pass between the plurality of substrates. (Refer to Japanese Unexamined Patent Application Publication No. 2000-306904.)
In a general thermal process, when a process gas is supplied into a heated process chamber, the process gas supplied into the process chamber is pyrolyzed and active species are thus generated in a radical state and deposited on a substrate to form a film. In a structure of a general process chamber, since a region in which the process gas is pyrolyzed is large, a plurality of types of active species that cause undesirable results involving non-uniform film thickness and non-uniform film quality within or between planes of substrates may be present among active species.